Labor’s frontbench suddenly looked a whole lot lighter at the end of the last Question Time in the current sittings yesterday.  Not only was Kevin Rudd, policy wonk and erstwhile Prime Minister, no longer there (he lasted 55 minutes of Question Time, a gutsy effort), but Lindsay Tanner rose at the end and sprang a shock that came right out of the political blue:  he was leaving politics.

That Tanner’s parliamentary career mostly coincided with Labor’s long years of Opposition, bookended by single terms in Government, meant we were deprived of the services of one of the best, smartest and most effective of the current political generation in high office.

Talking to him was like a breath of fresh air, to discover that senior politicians could be rigorous but heterodox thinkers willing to go beyond not merely the standard talking points that are now a critical part of most ministers’ armor, but straitlaced partisan thinking of any kind. It was always telling, I thought, that when he rose in Question Time to deliver his invariably savage deconstructions of a particular Opposition member or policy, he did so reading hand-written notes. Not for him the Departmental Question Time Brief or PPQ brief with some political tweaks added by staff.

Perhaps that’s why Tanner was never guilty of one of the most irritating mannerisms of the Rudd Government, the incessant repetition of whatever catchphrase was currently in vogue, whether “working families” or “tradies” or whatever other cliché had been conjured up in Rudd’s office for mass broadcast.

Tanner’s parting speech, announced in the chamber, elicited rare applause and generous words from all sides.

Rudd’s departure — in altogether different circumstances in the Prime Minister’s Courtyard earlier — was one of the more remarkable moments in political life. I noticed a few people on Twitter having a go at Rudd as he struggled to get his words out, but I can’t see how anyone could have watched those long, long silences and not felt for him, regardless of what they thought of the man’s contribution to political life.

There seems to be a golden rule of Australian politics now, that politicians are at their best when facing or experiencing defeat. Under challenge, they suddenly and dramatically lift their game.  he gold standard is Malcolm Turnbull’s astounding performance as his leadership was assailed by a right-wing putsch, meeting his challengers head on and vowing to fight, apparently against all odds, to head them off.

Even Rudd at his press conference late on Thursday night suddenly found the communications skills that had gone AWOL for most of his Prime Ministership, succinctly summing up his case for keeping the leadership and vowing to fight.

In defeat, like Malcolm Fraser — another Prime Minister considered cold and stoic — he succumbed to public tears. Perhaps, to indulge in the sort of Citizen Kane-like psychobabble hunt for a Rudd “Rosebud” that is lately fashionable, it was all that emotion repressed while in office that could suddenly be released. Or maybe, like a lot of us, he just has trouble keeping the tears away when something wrenching and deeply wounding happens to him.

Some suggest we shouldn’t feel sympathy for vanquished leaders, as though their pain is reward for their being ambitious. And it’s true that you don’t get to be Prime Minister without being extraordinarily, frighteningly ambitious. But ambition doesn’t abrogate the basic rule that there are few if any Federal MPs who aren’t there for the sole reason that they want to make Australia a better place.

Maybe that’s changing as more State Government-style machine men enter Parliament, but as a rule it still holds, even for those who make it to the very top. Rudd, who could readily idle away his time as a consultant or foreign policy guru given his financial circumstances, is no exception. Losing the best opportunity in the country to make a real difference is deeply wounding to such people and the pain isn’t just because their ambition has been thwarted.

Fortunately Thérèse Rein was there to support Rudd as he threatened to dissolve into tears. Rein has been a class act as the local equivalent of First Lady, especially given she’s continued her own business career while putting her own stamp on the traditional philanthropic duties of her position. Looking at this intelligent, talented, successful and eloquent woman, you can’t help but wonder whether she’d have made a pretty reasonable political leader too.

Still, three-and-a-half years ago it was Beazley’s distress at his loss that caught our attention, as Kevin Rudd snatched away the leadership (and like Rudd, Beazley had a fairly healthy poll position when he was rolled). And who knows when Julia Gillard will find herself trying to hold back her emotions as she confronts the reality of defeat.

It comes to just about all democratic leaders, no matter how successful, sooner or later. The only question is how long it can be delayed.